Low-water alarm



J. C.'McCARTHY LOW WATER ALARM.

APPLICATION FILEYD MAR. 16, 19:4.

1 1 96,005 Patented Aug. 29, 1916.

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JOHN C. MCCARTHY, OF FOB/l WAYNE, INDIANA.

LOliV-WA'IEB ALARM.

Application filed March 16, 1914.

To all whom it may concern Be it known that 1, JOHN C. MCCARTHY, a citizen of the United States of America, and resident of Fort Wayne, in the county of Allen and State of Indiana, have invented certain new and useful Improvements in Low-Water Alarms, of which the following is a specification.

This invention relates to improvements in water level indicators and low water alarms for steam boilers, and the object thereof is to afford a simple and reliable device for the purpose of ascertaining the state of level of water in the boiler, at normal stages, and to cause an alarm to be sounded when the water recedes to an abnormal level.

Another object is to so form the device that its operating parts will not be subjected to disturbance by the rolling action of the water in the boiler.

These objects are accomplished by the construction illustrated in the accompanying drawing which shows a side elevation partly cut away and in section, and referring to the various parts of the device and the corresponding indicating characters marked thereon: (A) is a hollow casting having a. vertical chamber (13), at the top of which is a horizontal branch (C) and at the lower end of which is an enlarged chamber (D). At the top of the casting, immediately over the vertical chamber is a connecting pipe (E) that afiords communi cation between the chamber (B) and the boiler (F) through an interposed valve (G). The enlarged chamber (D) likewise has communication at its lower end with the boiler through a pipe (H) and intervening valve (J). The valves used in making the connections between the device and the boiler are of the well-known type ordinarily used for water gage connections.

A rod (K) extends through the vertical chamber (B) and enlarged chamber (D), its upper end extending loosely through a spider (L) in the pipe (E) and its lower end extending loosely through a spider (M) in the pipe (H), the spiders each serving as a guide for the rod and at the same time allowing communication for the passage of steam and water into and out of said chambers. Fixed upon the rod (K) and ex tending within the enlarged chamber (D) is a hollow cup (N) that is closed at its top Specification of Letters Patent.

Patented Aug. 29, 1916.

Serial No. 824,913.

but has a series of openings (P) near its top for theedmission of water into the cup.

VVithin the horizontal branch (C) is a lever (Q) mounted upon a. pivot (R), the rear end of the lever extending through a slot (S) in the rod (K) and the outer end of the lever having fixed thereon a weight (T). Arranged vertically through the horizontal branch is a tube (U) which is closed at its bottom by a: cap (V) and is connected at its top with a whistle (7). Within the tube (U) is a valve (X) that is held against its seat (Y) in the upper part of the tube by: the lever (Q) that extends loosely through both the valve and the tube. Openings (Z) made in the tube at the seat (Y) serve for the outward passage of steam to the whistle when the valve is lowered. The outer end of the branch (G) is closed by a cap (0) which is of sufficient pro-portions as to inclose the weight (T) and admit of the necessary movement therein of the weight to seat the valve. The side of the casting (A) has secured thereto a sight-glass (A) that incloses the vertical chamber (B), the glass being preferably of the well known grooved gaged glass type.

In the operation of this invention the valves (G) and (J) are manipulated as with an ordinary water gage. When the water in the boiler reaches a level above the enlarged chamber (D) it shows through the grooved glass (A), and the cup (N) becomes filled with water through its openings The weight (T) is of such heft as to counterbalance the cup filled with water when submerged and hold the valve against its seat through the medium of the pivoted lever (Q) and therefore there is no passage of steam to the whistle. The variations of the level of Water at normal stages may be observed through the sight-glass, and such variations do not interfere with the water filled cup nor the mechanism operating therewith. in the boiler recedes to a point below the cup, or thereabout, the level of water in the chamber (D) likewise recedes leaving the cup and its contents of water in suspense, and therefore, the weight of the cup and its contents of water will cause the lever to swing upon its pivot and move the valve (X) from its seat, thus allowing steam in the branch (C) to pass through the open- However, when the water level ings to the whistle, the sounding of which is intended to signify that the level of water in the boiler has receded to a dangerous stage. As the water in the boiler is replenished, it rises in the enlarged chamber (D) and again submerges the cup and shows through the sight-glass, and the weight causes the lever to swing upon its pivot and raise the valve to its seat, thus stopping the passage of steam to the whistle, its silence signifying that the level of water in the boiler has raised from a dangerous stage.

By placing the cup and its appurtenances external of the boiler with the valve communications therewith, the effectiveness of the appliance is in no way impaired by the rolling action of the water in the boiler, such as is ordinarily occasioned in boilers of locomotives, vessels and other moving steam power apparatus.

hat I claim is 1. In apparatus of the class described, a

tion and having also fixed relation with the movable rod; a weighted lever pivoted in the branch of the member and having actuating connection with the movable rod; a steam operated signal having communicating means with. the interior of the member; and a valve actuated by the lever for controlling the passage of steam to the signal.

2. In apparatus of the class described, a chambered member having an enlarged bottom portion and a horizontal branch at its top; a sight-glass with means in connection therewith for attachment to the member and forming the front wall thereof; a cup in the enlarged portion of the member having one or more openings in its upper portion and having a stem extending up through the vertical chamber in the member there being provided a bearing for said stem at its lower and upper ends respectively; a steam actuated signal having communication with the chamber through the branch thereof; a valve for controlling the passage of steam to the signal from the branch; and a weighted lever pivoted in the branch and having connection with the valve and stem.

In testimony whereof I aflix my signature, in presence of two witnesses.

J OHN O. MoGAR-THY.

Witnesses MATHILDA METTLER,

WV. G. BURNS.

Copies of this patent may be obtained for five cents each, by addressing the "Commissioner of Patents, Washington, D. C. 

